Manufacture of starch.



L. P. BAUER & T. SPEGK.

MANUFACTURE OF STAROH. APPLIOATION FILED JAN. 17. 1908.

Patented Mar. 14, 1911.

s sHEnTssHEnT'1.

L. P. BAUER & T. SPEGK.

MANUFACTURE OF STARGH.

APPLICATION FILED JAN.17. 1908.

* Patented Mar. 14,1911.

heuwew L. P. BAUER & T. SPEGK.

MANUFACTURE OF STAROH. APPLICATION FILED JAN.17,1908.

Patented Mar. 14, 1911.

3 SHEETSSHEBT 3.

UNITED STATES PATENT oF noE.

LOUIS P. BAUER. AND THEODOB SPEGK, 0F CHICAGQILLlNdIS; SAfiJ SPECKAssIGl loit To SAID BAUER.

MANUIACTURE or STARCH.

Specifldation of Letters Iatent.

Patented Mal. 14, 1911.

Our invention has for its object to provide 5 a simple and novel processof separating and recovering substances which are held in suspension ina liquid medium which also contains impurities Where the natures of sucha substance and the impurities are such that the one or the other has aroster specific gravity or a greater capability of settling undercertain conditions.

We have found that by causing a thin layer-"of watery raw starch to movegently over 'a smooth surface, or without coming into contact withobstructions, a very large per cent. of the starch in pure form willsettle and, after such settling, there will be no re-mixing of theimpurities with the starch if the impure water is not allowed to standso as to permit the impurities to settle.- In accordance with ourinvention the settled starch is controlled in such a manner that thereare formed no solid masses of starch which may offer rough or unevensurfaces over which the impure watery mixture must fiow. We accomplishthis by gently removing the starch as fast as'itsettles and before ithas time to become packed'or asked, care being taken that there is noagitation which mightagain result in' an admixture of the impuritieswith the starch. By preventi n the settled starch from being againrendered impure, the presence of the usual attendant who scrapes thesurface of the deposited starch is made unnecessary. By recovering thestarch in liquid form, gravity does the work of the shovelers in the oldprocess, thetransportationof the starch becomes simply a matter ofpiping. By removing the stare as fast as it settles the process is madecontinuous.

,We have found that the best Way of recovering the precipitated starchis to maintain a cop body or mass of watery starch in the form of acomparatively dense liquid; produce and maintain a gently-and slowlymoving layer of the. impure mixture over this body or mam; collect thestarch upon this mass as it settles, withdraw starch from the bottom ofsaid mass at a rate corresponding to that of settling; and allow themixture, after being largely exhausted of starch, to be gentlydischarged at its own level at a rate sufficient to maintain the depthof the layer constant within reasonable limits. By withdrawing thestarch from the bottom of a deep mass, and one which has considerablecross-sectional area, there is only a slow settling motion at the top ofthe mass-where itis in contact with the moving layer,and all danger ofdetrimental commotion or agitation is avoided.

Our invention may be practiced in various ways: For example, therawmixture may be ed upon a short, smooth, rigid table soarranged thatthere will be an overflow when the material covers the table to apredetermined depth; A deep broad ho per filled with pure watery starchma he provided atone end of the table an the starch, as it settles maybe gently moved and deposited in the hop er; The starch may then bewithdrawn rom the bottom of the hopper and the exhausted liquid heallowed to overflow at the end'of the table.

The various features of novelty which characterize our invention will.be hereinafter pointed out with particularity in the claims,- but for afull understanding of the invention and of its'variou's objects andadvantages reference may be had to the following detailed descriptiontaken in connection wi h the accompanying drawings whichshow apparatuswhereby our invention may be carried out automatically, said ap aratusforming the subject of a second app ication filed b us-concurrentlylherewith.

In the drawings, Figure I is aside elevation of a complete systemcontaining one unit; Fig. 2, is a plan View; and Fig. 3 an end view ofsaid unit; and Fig. 4 shows a detail.

We are illustrating automatic apparatus for practicing our invention,-it will of course be understood that such apparatus is not intended todefine the bounds of our invention, but only to show a highly developedmeans whereby our novel method may be carried out in an advantageous andeconomical manner.

Referringto the drawings, A, A indicate a pair of short shallowtroughs'or tables inclined slightly from the rear ends to the front endswhere both tables end in a single depending hopper B. The top of thetables near .the hopper and the upper portion of the front wall of thehopper, as at a and b, respectively are sloped so as to form, in effect,a W1 e mouth for the hopper. Near therear ends of the tables aretransverse partitions a" a of a depth somewhat less than that of theside walls of the tables; thereby forming transverse troughs across theends of the tables. Thesides of the hopper converge until they almostmeet at a point considerably below the tables and an outlet C isprovided at this point. From this outlet leads a pipe D which extendslaterally and then upwardly to a level approximately in the plane of thetables. The top of the front wall of the hopper rises to a levelsomewhat above the plane of the table.

E E represent a series of paddles or scrapers, preferably U-shaped asshown, which are carried upon endless chains or the like. There is a setof these scrapers or paddles for each table and they and theirsupporting chains are so arranged with respect to the; tables that thescrapers or paddles maybe causedto move slowly across the tops of thetables from the rear end to the end at which thehopper is situated.During this passage across the tables the scrapers or paddles referablyride directly upon the surfaces o 'the tables. The endless carriers forthe scrapers or paddles may be supported in any suitable manner, as forexam le, by-sprocket wheels F secured upon sha ts F mounted at oppositeends of the tables and extending transversely thereof. Motion may beimparted in "any suitable manner as for example, by means of a beltpulley F upon one of theshafts. If desired, rollers e running uponstationary tracks-A may be arranged upon the travelingcarriers adjacentthe points of connection between the scrapers or paddles, and

the traveling carriers. By roviding these tracks the proper relation isat all times maintained between the tables and paddles or scrapers eventhough the carriers should stretch and tend to sag.

G is a header arranged adjacent the rear end of the tables and providedwith a discharge pipe 9 at each table the outlets of these plpes beingdirectly above the transverse/troughs formed by the artitions a. Thereis a valve g in each 0 the pipes 9 sothat the header may be caused todis charge into any desired number of units or portions of units and beprevented from discharging into the others. While we have shown only asingle unit composed of two tables it will of course be understood thatenough individual tables or groups of tables arranged in the form ofunits will be employed to take care of the output ofzany particularfactory. The header G may be made to extend adjacent as many of. thetables as is convenient, it being of course understood that where it isnot convenient to use a single header a plurality of headers will beemployed. The header G ispref: erably supplied from a tank such as Hwhich in turn receives its supply from a pump I or other source. Thepump could be connected directly to the header but by interposing thetank or reservoir a steady pressure may be maintained within the headerregardless of variation in pressure in the pipe leading from the pump.The suction end of the pump is connected to a tank-or reservoir J. Thetank J, in the form of'ou'r invention illustrated, may and preferablydoes receive the watery mixture of'starch with gluten and otherimpurities directly after the bolting operation; for, as

will hereinafter appear the usual settling tank wherein a part of thewater is separated from the mixture may be entirely eliminated.

To practice our invention, the valve g in one of the pipes g is openedand the watery mixture of starch with gluten and other impurities ispermitted to flow upon the corresponding table. As soon as thetransverse trough is full a broad thin sheet of the mixture overflowsupon the table and starts on a course toward the opposite end. Thissteady overflow will be maintained as long as the supply lasts andtherefore there will be a slow and gentle flow across the table to thehopper. As in the old process, to which we have previously referred, thestarch settles more readily than the gluten and other impurities and,before any given portion of the flowing stream has traveled very far,the greater part of the starch will have settled upon the surface of thetable and directly above the table will be a stratum of gluten and otherimpurities which have begun to settle and also some starch which isstill mingled with the impurities. Assuming that the hopper has beenempty, the material will flowinto the hopper and fill it before it willoverflow at the front end of the hopper. The contents of the hopperwould now; be in substantially the same state as that of the mixture asit enters upon the table except that most of the starch would have beenremoved therefrom if the settled starch were allowed to lie upon thetable. However, the endless carriers are set .j J and not into the tankfor containing pure gradually built up by'the ineren'ients which thecolor becomes pure white andthe density 40 starch which must be removedvmanually.

'ho 'iper. As soon as the hopper has become no gluten or otherimpurities'cnter the This pipe is connected to a tank M for con of thepipe D'i's at such an elevation that when the overflow at the front endof the 1' also begin to flow through the pipe D and only a shorttime,however. before theoriginal-impureeharge of the hopper has been paddlesor scrapers.

the reservoir for containing pure starch.

-aeeasao a in operation. and the scrapeis orpaddles slowly move acrossthe face of the table and carry before themthe starch which has settledand finally push this sta'reh into the filledthe level of the fluid uponthe table rises until there is an overflow at the frontend of thehopper. Thereafter practically hopper as these. substances will he.carried with the cm'rentand overflow at theend of thehoppcr, The'endof-the. pipe" D pref; erably opens into the bottom of a receptacle Kfrom the bottom of which leads a pipe L.

taining.purestarch. -'lhere is alsoa branch l wh ch leads to the tank J.The outlet end hopper beginsthe contents of the hopper out of its upperend into the receptacle K. In starting under the conditions assumed, avalve Z arranged in the pipe L isclosed and a valve Z-"arrangedin thepipe Z- is opened. Therefore all of the material discharged intothe-receptacle K flows back to the tank starch; The apparatus need be inoperation entirely withdrawn and .its place taken by a mass of purewatery starch which is} are pushed into the top of the hopper by theTherefore, the. operator need only watch the color of the matcrialdischarged from the pipe D and when is high enough the valve Z may beclosed and the valve Z opened. All of the ma-- terial which thereafterflows out of the bottom of the hopper is then led directly to The starchas it settles upon the table does not immediately form into a hard massbut remains in a semi-liquid state so that by properly adjusting therate of movement of the carriers no difficulty will be experienced inkeeping the top of' the table clean and preventing the formation of ahard layer of enters upon one end of a table approximately 20 feet longmay be so modified that the density of the liqhid which overflow-stilefront end of thev hopper will be in the neighborhood of 2 degrees Bau newhile the density of the watery starch which is de livered from thebottom of, the. hopper may 7 have a. densityot 15 degrees Bunnie ormore. If (lGSll'td, the mixture which overflows at the front end of thehopper mayabe carried over another table where some ofthc starch wlnchhas been kept in suspension to-v gether with the gluten andotlierimpnrities will settle. and the density of the mixture as it finallyoverflows at the end of the second -y table be reduced still more.

nearly so rapidly'as' the starch. In the The gluten and otherinipdrities tend also to settle but not usual process it is necessaryfor attendant-s to closely watclrtlte tablesand scrapefrmn the surfaceof the settled starch any accus mulation of gluten and other impuritieswhich may take place. By making the tables which form partof thepresent-apparatus fairly short, the impurities including? I i the glutenmay be carried entirely across the tablc before they have an opportunityt'0.-:' settle with the, starch and the only impu'rities which remain inthe starch which is discharged from the hopper comprise those;

ble to remove byany process.

small traces which it is practically impo'ssi-J The pipe D is preferablyiniade adjusts,

able so that the head which sei'vcs'to-forcc- 1 the starch through thispipe may. be nicely adjusted so as to secure the best results- Xconvenient arrangement consists in having:

at the .upper end of thepipe D a small section. of pipe at which may;bescrewcd into and out of the main pipe 'sutlieie ntly to vary' thelevel of thcdischarge outlet within any, desired limits. Similarly, itis desirable to provide means for varying the level which the liquidupon a table must reach before it overflows at the front end of thehopper,

better results being obtained in some cases.

with one depth of liquid upon the table while in other instances adifferent depth is advisable, depending upon the nature of the materialwhich is being treated.

As hereinbefore stated, the glutcn'fand other impurities, together withsome of the starch, settle partially in the flowing stream.

so that there is a perceptible layer of impurities mixedwith starch veryclose to the surface of the table. In order to prevent;

this impuremixt-ure from being drawn into the hopper as'it passes acrossthe topjthereof we prefer'to prov de an auxiliary outlet at the fronte'ndof the hopper in approximately the plane of the layer of impurities.This outlet may conveniently conslst ofaj plurality of perforations b inthe wall b'of .the hopper. the perforations lying very near the plane.of the top of the table. When the depth of the-material upon the tableis ,varied. the depth to which 5 the impurities sink varies also;andfifdesired, the same means may-be used'for adjusting the. height "ofthe liquid upon the table the screws 1) are loosened, the ,n emberb israised or lowered as the case: may be, and tliescrewsare again tightenedso'a's to retain the member 6 in its ad'justedpositioni This particularad-" justment may be effected in .any'other desired way however. I

The water .and' 'impuritiesflwhich 'overflow at the front end of thehopper may be receivedin a trough N which-extends ad- .jacent anydesired number of tablesor units and conducts the overflow "to i any '1desired It will be seen" that the"serapers "or-pad; dles'remove thestarchas fast as it' settles and deposit'it into the top of the'-hopper. The surface over which the mixture fiowsis thereforealwaysfkept smooth and even' and there is little "possibility ofobstructing theliow of thepartiall settled layer of gluten and otherimpurities. When thehopper is reached the starch gradually movesdownward over the inclined portion a of the' table so that thereisno-suddenchange of current, and the watery mixture containing theimpurities flows freely across the top ofthe hopper and is discharged ata point considerably in front of the main portion of the hopper. Thecross-sectional area of the hoppers near the 'top'thereof is nade sufibciently great to prevent a'ny disturbance or agitation-"due' 'to thedischarge through the comparatively small outlet C, there being only agradual settling of the watery starch in the hopper and,'because of thecontinued addition ofsettled starch there is actually very littleapparent change in. the upper portion of'the hopper;

Since the starch has-a tendency to settle.

and to cake upon the surfaces over which it passes, the dischar e streamof pure starch should'be made as large as possible in order to'preventany such settling. It is obvious that a larger discharge stream can beob-- tained by combining the discharge streams from a pluralit of tablesand for this reason it is prefers; 1e though not essential, that .asingle hopper be emp1oyed in eonnectio with at least two of'the tables.

Q fl

the raw material.

.dram any unit the'proper valve 0 1S opened After the'vaIves theoverflow eontroL l ng devices, 12 and the pipes d have once been"carefully adjusted so as to make the i'conditions' at the discharge endsof the tables s'uchas'to produce'thc best results for a. given 'stream'which is flowing upon the tables,"no further attention needbe given tothe apparatus. Therefore any desired number oftablesmr groups of tablesmay be broughtinto operation or stopped by simply an operator; so that asingle attendant may be placed in'charge of sufiieient' apparatus toseparate'and recover the same amount of starch which-heretofore hasrequired a score or more of attendants.

n In case it should beTdesired to drain all of the material from anytable and its hopper, wehave provided a header 0 which is con net-ted toany desired number of hopper outlets,;thecommunication between theoutlets and the headers-being controlled by valves .0.' Thisheader maybe connected to the pipe 1 which leads to the reservoir'J containingWhen it is desired to and'the contents of the unit flow into the headerand thence to the reservoir J.

It is not necessary, in starting the apparatus. to permit the hopper tobecome filled with the raw mixture, but a supply of pure starchmay beprovided so that the hopper may be filled therewith before the stream ofraw starch is turned on. Any suitable arrangement may be provided forconveniently filling the hoppers, as for example, there may be anauxiliary reservoir P corresponding to the reservoir H, the reservoir Pcontaining pure watery starch.

' Q, is a header similar to the header G and g, g are pipes leading fromthe header Q to the hoppers of the tables with which the header isassociated.

p is a valve controlling the supply of starch from the reservoir to theheader and 51' q are valves in the pipes g g.

-The reservoir P may obtain its supply in any suitable manner.- Thusthere maybe a pipeirleading into the top of this reservoir from thedischarge side of the pump R which normally'serves to pump the waterystarch from the main reservoirM and forceit into a pipe line 1''.Theremay be valves r and 7* respectively in the pipe r and in the pipeline 1'' so that the ump may be made to'supply only the tank or the pipeline.

-' Itj1s sometimes necessary to stop the separating operations at someof the tables for a short time,'in which case it would not be economicalto drain the tanks or permit the starch in the hoppers to remain quietso as to permit settling and packing of the starch in the hoppers. Whenit is desired'to thus.

' temporarily shut down some of the tables,

the header Q is placed in communication with the reservoir P and thevalves g in the proper pipes g are opened. Therefore pure starch flowsthroughsome of the pipes 9 into the hoppers with which they are associated and is discharged from the bottom of such hoppers through the pipeD and returns to the main reservoir. If the reservoir P is a small oneor if the tables are to remain inactive for a considerable period, thepump B may be made to supply the auxiliary reservoir with starch as fastas it is taken out of the reservoir. Thus a natural circulation of purestarch may be maintained throughout the inactive hoppers and the hoppersand the pipes leading therefrom will be maintained clean so that, all ofthe tables may again be ments notice.

The tables and hoppers are preferably made of metal so that they willretain their shapes and theirinner surfaces will remain smooth under allconditions. Of course it is not necessary to make these parts of metalbut we believe it would be preferable for the reason that wooden tableswarp and become uneven, thereby interfering with the efiiciency of theoperation. The paddles or scrapers are also preferably formed so thattheir upper edges will lie below the sur face of the moving stream,thereby permitting a natural flow of the-main portion of the stream andavoiding the formation of eddy currents which mi ht result in mixingimpurities with the precipitated starch.

Where the partially exhausted mixture is passed over a second table orset of-tables placed in operation at a mo- .the same adjustments aremade as at the first table or set of tables and thereafter no furtherattention need be given thereto since the supply of mixture will besteady and uniform. The entire separating and recovering process istherefore accomplished automatically and continuously and there need beno cessation in the operation in order to permit the removal of thestarch. Furthermore all of the starch which is recovered is in pure formand there is no need for retabling a portion thereof as in the'case ofthe old process where there is always an accumulation of impure starchat each end of the tables.

Having now fully described our invention, what we claim as new anddesire to secure by Letters Patent is 1. The method of recovering purestarch from a watery mixture containing the same and impurities of lessspecific gravity, which consists in supplying said mixture so as tomaintain a gently moving shallow layer which will permit the starch tosettle, collecting the settled starch upon the top of a comparativelydeep body of pure watery starch lying directly beneath said layer,withdrawing watery starch from a point adjacent to the bottom of saidbody at approximately the rate at which the starch settles, andwithdrawing the exhausted water and the impurities remaining therein ata point above said body and at a rate which will maintain the thicknessof said layer approximately constant, said mixture being supplied atsuch a rate that the starch may be withdrawn rapidly enough to preventcaking of the starch composing said body.

2. The method of recovering pure starch from a'watery mixture containingthe same and impurities of less specific gravity, which consists insupplying such mixture so as to maintain a gently-moving shallow layerwhich will permit the starch to settle, col lecting the settledstarchupon the top of a comparatively deep body of pure waterystarchlying beneath said layer, withdrawing the watery starch from apoint adjacent to the bottom of said body, and withdrawing the exhaustedwater and impurities remainin therein at a point above the top of saidbo y.

3. The method of recovering in pure form starch contained in a waterymixture of the same containing impurities of less specific gravity,which consists in producing a shallow gently moving stream of saidmixture so as to permit the starch to settle, collecting the'starch asit settles by means independent of the stream and in sucha manner as notto agitate the stream, and causing the collected starch and theremaining impure mixture to be divided into independent substreamsbranching respectively from the bottom and from the top of the mainstream. 4. The method of recovering pure starch from a watery mixturecontaining the same and gluten, which consists in producing a slowly andgently moving shallow stream of said mixture so as to permit the starchto settle, causing jsaid stream to flow over a comparatively deep bodyof watery starch, moving the settled starch positively and independentlyof the flow of the stream in the direction of flow of the stream untilit is deposited upon said body, and withdrawing.

over a comparatively deep body of watery starch, moving the settledstarch positively and independently of the flow of the stream until itreaches said body, Withdrawing the Watery starch from the bottom of saidbody and withdrawing said impurities and the exhausted water from apoint above said body.

In testimony whereof, we sign this specification 1n the presence of twowltnesses.

LOUIS P. BAUER. THEODOR SPEGK Witnesses:

RUBY V. NASH, WM. F. FREUDENSEICH.

